Connecticut counties by area
Official, comparable measurements for 9 counties and county equivalents.
- 140.2–367.3 mi²
- 412.8–424.1 mi²
- 532.1–553.9 mi²
- 598.1–786.6 mi²
- 1,027.4 mi²
- 146–177 per mi²
- 418–475 per mi²
- 968–1,122 per mi²
- 1,204–1,576 per mi²
- 2,409 per mi²
Understanding Connecticut’s county areas
The land-area range runs from Greater Bridgeport Planning Region at 140.2 mi² to Capitol Planning Region at 1,027.4 mi². The largest has 7.3 times the land area of the smallest and accounts for 21.2% of the combined county land in Connecticut. Compare with every state’s largest county.
The median county-equivalent land area is 532.1 mi², below the national median of 604.5 mi². The median describes the middle of the county size distribution; it does not describe how people or development are distributed. A state with a few very large counties can have a much smaller median than its largest entry suggests.
Where water changes the picture
South Central Connecticut Planning Region has the most assigned water area, at 252.3 mi². Greater Bridgeport Planning Region has the highest water share, with water making up 41.1% of its total area. Water area and water percentage answer different questions: the first measures an amount, while the second measures the mix of land and water.
Across all 9 entries, water accounts for 12.6% of the combined total area. This is calculated from the summed land and water measurements, rather than averaging county percentages, which would give each small and large county equal weight.
Where people live
An estimated 3,688,496 people lived in Connecticut on July 1, 2025 (+2.2% since 2020), or 1.1% of the national total in this dataset. Capitol Planning Region is the most populous county equivalent, with 994,115 residents — 27% of the state. It is also the largest by land area.
Across the state there are 762 people per square mile of land. County densities range from 2,409 in Greater Bridgeport Planning Region to 146 in Northwest Hills Planning Region; the median county equivalent has 968. Switch the map above to density to see where the state’s population concentrates.
Compare the largest and smallest county equivalents in Connecticut to see land, water, and total area on the same scale.
These calculations use the 2026 Census county records listed below. County-equivalent boundaries vary between states; area alone does not measure population, density, or usable land. See coverage and calculation rules.
Complete area table
Sorted from largest to smallest land area.
| # | County / equivalent | Land | Water | Water share | Population | Per mi² |
|---|---|---|---|---|---|---|
| 1 | Capitol Planning RegionGEOID 09110 | 1,027.4 mi² | 18.8 mi² | 1.8% | 994,115 | 968 |
| 2 | Northwest Hills Planning RegionGEOID 09160 | 786.6 mi² | 21.5 mi² | 2.7% | 114,690 | 146 |
| 3 | Southeastern Connecticut Planning RegionGEOID 09180 | 598.1 mi² | 83.6 mi² | 12.3% | 284,015 | 475 |
| 4 | Northeastern Connecticut Planning RegionGEOID 09150 | 553.9 mi² | 9.3 mi² | 1.6% | 98,096 | 177 |
| 5 | Western Connecticut Planning RegionGEOID 09190 | 532.1 mi² | 115.9 mi² | 17.9% | 640,482 | 1,204 |
| 6 | Lower Connecticut River Valley Planning RegionGEOID 09130 | 424.1 mi² | 93.1 mi² | 18% | 177,311 | 418 |
| 7 | Naugatuck Valley Planning RegionGEOID 09140 | 412.8 mi² | 8.8 mi² | 2.1% | 463,349 | 1,122 |
| 8 | South Central Connecticut Planning RegionGEOID 09170 | 367.3 mi² | 252.3 mi² | 40.7% | 578,741 | 1,576 |
| 9 | Greater Bridgeport Planning RegionGEOID 09120 | 140.2 mi² | 98 mi² | 41.1% | 337,697 | 2,409 |